A notable feature in our analysis is the increased uncertainty in the spin magnitude distribution as compared to that from the Beta distribution in spin magnitude. The motivation for using a Beta distribution in [1]}, [2]}, [3]} is not physical but is statistical: the Beta distribution offers a flexible, parametric fit for the mean and variance of a distribution and has an analytic form. The spline model introduced in this work offers more flexibility than the Beta distribution, so lacking a physical motivation for the Beta distribution, we expect that the uncertainties in the spin magnitude distribution obtained in this work are more appropriate than those obtained from the Default model. Furthermore, the Beta distribution used in [2]}, [3]} cannot model structures such as increased support for nonspinning BHs or a secondary peak at high spin, making it a suboptimal model for the astrophysical spin magnitude distribution in the presence of a nonspinning subpopulation. Comparing to our data-driven approach, we therefore conclude that the resulting spin distribution presented in [3]} is partially model-driven rather than data-driven.
